Okay, just to add my two cents again. I do warm up both scales. No, I do not have any lighting in my reloading room that would affect the scales. After, doubling checking the RCBS scale against both beam and the i120, it does not throw consistent enough loads for me, for my long range shooting. If you're only using the RCBS, you really have no way of checking how close each load is, unless you have something to compare it with. I originally thought it was pretty close until I bought the i120. After the RCBS has stabilized and it says the load is perfect, I then double check that load on the i120. The variance was too much for me, up to .5 =/- (which means two comparable loads could be off one full grain). Depending on age, gender, income, and present stage of marriage, some may feel the i120 is to expensive. I get that. But for me it works and when I screw up a shot, I know it's not the load, it's me.... Cheers everyone!